IGF::OT::IGF ICING IS A SIGNIFICANT AVIATION HAZARD, AND ICING CONDITIONS CONTINUE TO BE DIFFICULT TO PRECISELY FORECAST OR LOCATE IN REAL TIME. AN IN-SITU SENSOR, WHICH CAN BE FLOWN COUPLED WITH A RADIOSONDE, IS NEEDED WHICH CAN BOTH MEASURE SUPERCOOLED LIQUID WATER CONTENT IN CLOUDS AS WELL AS CHARACTERIZE THE DROPLET SIZES. THIS SENSOR WILL SUPPORT THE CALIBRATION AND VALIDATION OF REMOTE-SENSING METHODS USED TO DETECT ICING CONDITIONS, AND CAN ALSO BE USED ON ITS OWN TO SUPPORT OPERATIONAL METEOROLOGY APPLICATIONS. ANASPHERE, INC. PROPOSES TO DEVELOP A SIZING SUPERCOOLED LIQUID WATER CONTENT (SSLWC) SONDE WHICH WILL MEET THIS NEED. IT WILL BE BASED ON PROVEN VIBRATING-WIRE TECHNOLOGY WHICH HAS BEEN USED FOR TOTAL WATER CONTENT MEASUREMENTS, BUT WITH AN ALTOGETHER DIFFERENT PHYSICAL IMPLEMENTATION THAT WILL ENABLE DROPLET SIZING. PHASE I WILL INVOLVE THE AERODYNAMIC DESIGN OF THE SSLWC SONDE, ICING TUNNEL TESTS DEMONSTRATING KEY ELEMENTS OF ITS FUNCTION, AND A LIVE FLIGHT TEST TO GATHER INFORMATION ON THE SONDE'S AERODYNAMIC CHARACTERISTICS. PHASE II WILL INVOLVE FURTHER TUNNEL TESTS, LABORATORY CALIBRATION DEVELOPMENT, DESIGN FOR MANUFACTURABILITY, AND FLIGHT TESTS IN ICING CONDITIONS.